2. The genus Triticum
โข Poaceae
โข Highly inconsistent taxonomy
โข Triticum and Aegilops separate genera
โข Triticum sensu lato
โ Includes Aegilops
โข Triticum sensu stricto ~ 10 species
โข Native to Mediterranean area
โข Base n = 7
3. Domesticated Wheats
โข Triticum monococcum L. (cultivated einkorn)
โ T. boeoticum (wild einkorn)
โ Diploid - AA
โข Triticum dicoccum Schรผbl. (emmer wheat)
โ T. dicoccoides (wild emmer)
โ Tetraploid โ AABB
โข Triticum aestivum L. (bread or common wheat)
โ Hexaploid - AABBDD
โ T. dicoccoides (AABB) + Aegilops tauschii (DD)
6. CHROMOSOME NO. AND PLACE OF ORIGIN
Ploidy level Chromosome no. Place of origin
Diploid : 2n = 14 Asia minor
Tetraploid : 2n = 28 Abyssinia, North Africa
Hexaploid : 2n = 42 Central Asia
7. Ploidy
level
Species Common name Genome
Diploid
(2n=14)
T. boeticum
(T. aegilopoides)
T. monococcum
T. speltoides
T. tauschii
Wild einkorn
Einkorn (Culti)
Wild goat grass
Wild
AA
AA
BB
DD
Classification
8. Ploidy level Species Common name Genome
Tetraploid
(2n = 28)
T. dicoccoides
T. dicoccum
T. durum
T. persicum
T. turgidum
T. polonicum
T. timopheevi
Wild Emmer
Emmer (Culti)
Macaroni wheat (C)
Persian wheat (C)
Rivet wheat (C)
Polish wheat (C)
Timopheevi (W)
AABB
AABB
AABB
AABB
AABB
AABB
AABB
Classification
9. Ploidy level Species Common name Genome
Hexaploid
(2n=42)
T. aestivum
T. compactum
T. sphaerococcum
T. spelta
T. macha
Common /bread
Club wheat
Dwarf wheat
Spelt wheat
Macha wheat
AABBDD
AABBDD
AABBDD
AABBDD
AABBDD
Classification
10. T. boeoticum (T.aegilopoides)
(Wild einkorn) (AA)
Natural mutation and selection
T. monoccocum
Cultivated diploid
AA (2n = 14)
Origin of diploid wheat
11. T. monococcum x T. speltoides
AA BB
(2n = 14) (2n = 14)
F1 sterile (2n = 14) (AB)
Natural mutation and Doubling
T. dicoccoides (2n = 28)
Wild emmer AABB
By natural selection
T. dicoccum (Emmer wheat)
AABB (2n = 28) Cultivated
ORIGIN OF TETRAPLOID WHEAT
12. T.dicoccum x T. tauschii
AA BB DD
(2n = 28) (2n = 14)
F1
ABD (2n = 21) - Sterile
Natural doubling
T. aestivum
AABBDD (2n = 42)
(Cultivated)
Origin of hexaploid wheat
13. Evolution of hexaploid wheat
T. boeoticum x
T. speltoides
T. tauschii T. aestivum
T.dicoccoides
T. dicoccum
15. The evolution of hexaploid bread wheat from its wild
relatives.
T. monococcum x T. speltoides
AA BB
(2n = 14) (2n = 14)
F1 sterile (2n = 14) (AB)
Doubling (2n =
28)
X Aegilops squarrosa
3x = 21
Doubling
6x = 42 AABBDD Hexaploid
wheat
16. 1. T. boeoticum (Wild Einkorn)
โข Primitive type from which other species have evolved
โข With one to two seeded spikelets.
โข It is the ancestor for all the cultivated wheat
2.T.monococcum (Cultivated Einkorn)
โข Primitive diploid form domesticated, evolved from
T. boeoticum by mutation and selection.
3.T.dicoccoides (Wild Emmer)
โข Amphidiploid form from the hybridization of T. boeticum and T.
speltoides.
Related species of Triticum
17. 4.T.dicoccum (Cultivated Emmer)
โข Developed throโ natural selection
โข The spikelets are two grained
โข Grains retained within the glumes after threshing (speltoid).
โข It is the oldest of the cultivated wheat.
5.T. durum (Macroni wheat)
Free threshing; wheat with naked grains
Important of the tetraploid wheats.
Grains contain high gluten.
โข
Related species of Triticum
18. 6. T. speltoides (wild)
โข Naturally cross pollinating
โข Recognized donor of the B genome.
7. T. tauschii (wild)
โข Source of D genome in the cultivated hexaploid wheat, which has high
adaptability.
Related species of Triticum
19. The cultivated wheat is classified into two
Types of wheat
Winter wheat
โข Long duration
cultivated during
October โ November to May - July.
Spring wheat
โข short duration
cultivated during
March - May to August โSeptember